优选：精密管企业

山东大鼎钢管厂The large stress and force at the upper yield point decrease firstly before yielding, and the lower yield point (_sl): the small stress at the yield stage is independent of the initial instantaneous stress. The yield point formula is: formula: FS yield strength (constant) in tensile test, N (Newton) SO original cross-section area, MM2. Fracture elongation (Sigma) In tensile tests, the percentage increase in the standard distance 山东大鼎金属材料有限公司between the specimens and the original standard distance is called elongation. The average daily capacity of copper in a year is expressed in sigma, with a unit of%. The formula is: Type: gauge length of L1 - after fracture, mm, L0 - original gauge length, mm. Section shrinkage山东大鼎钢管厂冷拔无缝钢管具有内外壁无氧化层、高压无泄漏、精度高、光洁度高、冷弯不变形、平整无裂纹、表面防锈处理等特点。主要用于汽车、摩托车的机械结构、液压设备和气动或液压元件。冷拔无缝钢管生产的工业控制包括模具设计、退火、酸洗、润滑等条件。同时，要搞好毛管质量检查和维修工作。